Naloxone has the following structure and is synthesized from thebaine:

Naloxone is most commonly used to treat patients suffering from opioid dependence or overdose because it is a competitive μ-opioid antagonist that blocks the effects of opioids. Naloxone is currently available in Suboxone® (Suboxone is a registered trademark of Reckitt Benckiser Healthcare (UK) Limited) as tablet or sublingual film strip formulations. Suboxone® contains buprenorphine and naloxone in a 4:1 ratio. Naloxone is also available as an aqueous nasal spray under the trademark Narcan® (Narcan is a registered trademark of Adapt Pharma Operations Limited LLC, “Adapt Pharma”), which contains 4.42% w/w naloxone hydrochloride dihydrate, 0.01% w/w benzalkonium chloride (“BKC”) as a preservative, 0.74% w/w sodium chloride as an isotonicity agent and 0.2% w/w edetate disodium dihydrate (“EDTA”) as a stabilizing agent. Adapt Pharma has U.S. Pat. Nos. 9,211,253, 9,468,747 and 9,561,117 listed in the U.S. Food and Drug Administration's Orange Book for Narcan® 4 milligram nasal spray. Each of these patents discloses and claims naloxone formulations containing an isotonicity agent. Additional Adapt Pharma also has U.S. Pat. No. 9,480,644 listed in the Orange Book for a 2-milligram naloxone nasal spray, which discloses and claims naloxone formulations that also contain an isotonicity agent. U.S. Pat. Nos. 9,192,570 and 9,289,425 assigned to Indivior, Inc disclose and claim naloxone nasal sprays that contain both citric acid as a buffer and benzyl alcohol as an anti-microbial agent.
One issue with other opioid dependence treatments is that they can become addictive. Naloxone, however, does not appear to be addictive and patients do not build up a tolerance.
Naloxone has also been used as a treatment for cognitive insensitivity to pain with anhidrosis. Insensitivity to pain with cognitive anhidrosis is a disorder in which the patient cannot feel pain.
Naloxone may be administered orally, intravenously, by injection or via the nasal mucosa. Naloxone has a low mean serum half-life when administered parentally. The quick metabolism may require repeat dosing or cause patient discomfort between doses. Enteral administration has low bioavailability due to hepatic first pass metabolism.
Accordingly, while there are some naloxone formulations currently available, there is a need for safe and effective liquid spray formulations that are stable including physically and chemically stable and contain naloxone, pharmaceutically acceptable salts or a derivative thereof.